Excellent rate performance and outstanding safety performance are factors which are considered in vehicle-mounted power batteries. Conventionally, a battery pack consists of at least one single battery. Therefore, the safety performance of every single battery should be considered in order to improve safety performance of the battery pack. On special occasions, the safety performance of every single battery will be deteriorated due to the low safety performance of the battery pack.
Battery explosion prevention is the primary mission for improving battery safety performance in extreme conditions. Generally, an explosion-proof structure may be fixed in the battery to prevent the battery from explosion. Since battery pack is always designed with a leak-proof structure, if one single battery in the battery pack becomes abnormal and produces large amounts of gas, the environment in which other single batteries located will also be changed, which may affect the normal work of other single battery or battery pack. Thus, to ensure battery safety, not only should the safety performance of every single battery be improved, but also an explosion-proof device may be applied in the battery pack.
However, because of the large volume and irregular shape of the power battery pack, it may be difficult to install an explosion-proof device, such as an explosion-proof valve, in the power battery pack.
Besides, to avoid battery explosion, an arcual, such as an L-shaped, cross-shaped or linear-shaped, dent may be carved on a battery shell. However, it may be difficult to operate under a low pressure in this manner. Moreover, an actuating pressure of the explosion-proof device may fluctuate in a large range, an exhaust area thereof may be small, and the gas emission may be non-uniform, which may not meet pressure releasing requirements for the power battery.